It has become a design trend for windows to include a grill to enhance the aesthetic look of the window. For example, U.S. Pat. No. 3,686,814 (Anderson) shows false muntin bars 20 and 22 positioned on a window.
Many different methods of attaching the grills to the window frame were developed. In U.S. Pat. No. 5,657,590 (Digman et al.), an end connector was shown (see FIGS. 3 and 4) for connecting a muntin bar to a window frame (see FIG. 1). The end connector included a spine, a stabilizing end, fins, a platform 38 and pins. The stabilizing end was inserted into open ends of the muntin bar and engaged with the holes to hold the bar in place. End connectors in U.S. Pat. No. 5,678,376 (Poma) and U.S. Pat. No. 6,425,221 (Reichert) operated in a similar manner.
A problem with the prior art approach was that it required the drilling of many holes in the window frame or glass frame. This involved much labor and could lead to broken seals in insulated glass packs.